ABCD

Example

A
C
C
19
B
B
A
_
B
C
C
11
11
_
19
 
 
A
B
C
_
_
_

Solution

A
C
C
19
B
B
A
11
B
C
C
11
11
11
19
 
 
A
B
C
9
1
5
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ABCD
ABCD

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